View Full Version : I'm confused about anti-fouling paint

08-09-2001, 10:53 AM
Is the only purpose of anti-fouling paint to stop the growth of vegetation/critters? Or does it also help protect the wood from rot and decay? I'm in the middle of the U.S.A and on a fresh water lake. Thanks in advance, this is my first post, but I've been reading and researching this site in the "stealth" mode for a few months. It's a great help to new boat owners such as myself, Randy

Keith Wilson
08-09-2001, 11:46 AM
The purpose of anti-fouling is to keep critters off. Anti-fouling is basically poison (generally copper oxide) with just enough paint to hold it to the boat. Ordinary paint will protect the wood better if you don't have to worry about marine life. I've also used epoxy with graphite (on plywood) below the waterline to good effect . Trailered boats don't need to use anti-fouling, and a lot of small boats here in Minnesota are kept on moorings with no anti-fouling at all (cold water, short season).

08-09-2001, 11:57 AM
RandyW.,The simple answer is no.
I dont know if any claims are made by mfgs.but all bottom paints are easily permeated by water.Their toxics release or the paint sluffs and wears out,so they are not a protective covering.
Underwater wood gets completely soaked and that actually prevents rot.
I'm sure the pros. can answer this better.
To my knowledge,the spores in the wood that spring to life as rot, are kick started by a certain % of moisture,combined with a specific temp.range and O2 level.That is why completely submerged wood does not rot where wood at frame ends near the keelson are frequently soft.Same for the wood at the waterline that cycles through wet dry periods and is under a swim step.

[This message has been edited by dasboat (edited 08-09-2001).]

[This message has been edited by dasboat (edited 08-09-2001).]

08-09-2001, 12:52 PM
Thanks much for the replies, the boat is a 42' and stays in the water year-round. I scuba'd the hull and there's no vegetation or growths on it and all the planks appear to be solid and tight with good paint on them. I hate to pull it just to put another couple of coats on when the current bottom seems to be doing a good job. Randy

08-09-2001, 02:33 PM
RandyW,coupla q's.Fresh or salt water?
Whydya scuba da bottom before?
How long havya owned her?
How familiar areya with tha waters yer in as far as groin stuff on bottoms?
Say more,because the answers may change>

08-09-2001, 04:14 PM
I'm in a fresh water lake in Missouri and the boat's a Trojan FBMY that I'm considering buying. Beautiful old boat, but people around here have a fear of wood boats. I've exhausted myself looking over the boat inside and out and wanted to make sure I knew as much as I could about it before I made an offer. So I put some gear on and spent some time underneath making sure that the bottom looked as promising as the bilge(very dry for a wood boat based on my limited experience). I've had a 33' Trojan for the past year or so and am learning as much as I can. Had some interesting times with my marina and am learning some lessons the hard way! Randy

Dale Harvey
08-09-2001, 04:41 PM
An old Trojan that dosn't have rot in the windows and deck edges, has spent its life kept in covered storage, or was reworked early on. If the shed dosn't come with the boat, it will be much more expensive to keep it going. Rot in the tops of the frames and deckbeams may work from the center out. Can be real hard to see. Check closely around the Keel/keelson area and top inside of the transom. Also stem and apron. Keep it in Missouri, as further south it will disintigrate no matter what you do to it.

Don Z.
08-09-2001, 04:42 PM
OK, I'll say it before Bob does.


08-09-2001, 05:00 PM
Surveyor is on the way (but I'm a curious fella who can't stand to let somebody else do ALL the poking and prying!). She does have a little dry rot just below the deck in two places, that's what made me worry about the bottom. We keep them in covered slips out here and she appears to have been well maintained prior to the current owner (who has moved away and cannot spend time on her).

08-09-2001, 05:11 PM
DonZ,Took the words out of the mouths of 90% of this forums members.
Randy W,your on the right track.Be sure your surveyor is very knowledgable about wood boats.
If there aren't many woodies in your area he may not have lots of experience,which is what you want.
Dont be shy about asking him to refer you to the last 3 or 4 woodies he has done.If he gives you references,do check them out.Also check with yards and brokers and see what his rep.is.
ps.There ain't a person on this forum who has not fallen love with a pretty pile of wood that floats.Be sure this is more than that.

[This message has been edited by dasboat (edited 08-09-2001).]

08-09-2001, 05:32 PM
Ha! According to my wife, I fall in love with piles of anything that looks like it needs a good home! "Look,Honey, this 42' boat just followed me home! Can I keep it??" Thanks to all of you for your help, I've asked the surveyor if I can tag along and have him explain what he finds and he thinks that would be a fine idea. We'll see what he finds that I've missed. Randy

08-09-2001, 07:07 PM
Go for it Randy.Hows about some pictures and narrative of the survey/purchase process???
First thing we do around here when followed home,and we both secretly know were going to keep it,is start thinking of names.
Soooooooo,Any names in mind...HHHHmmmmmmmmm?
Das http://media5.hypernet.com/~dick/ubb/biggrin.gif
ps.where is ashland?I grew up in St.louie,but that was in the olden,days as my children used to say.

[This message has been edited by dasboat (edited 08-09-2001).]

08-09-2001, 08:36 PM
I'll work on some photos and try to keep you updated with the process. Ashland is just a little town (1800 pop)located between Columbia and Jefferson City. We've got our current Trojan down at the Lake of the Ozarks and really enjoy it down there. My wife is not really enthused about trying to name this possible new purchase (if I feed it and name it, that makes it ours, doesn't it??), but we've kicked around the name "Ol' Smoke Eater" which is a reference to my occupation. Everybody has bad habits, mine just happens to be fixing up old things. I forgot to check your stats before I started typing this, where have you transplanted to?

08-09-2001, 09:38 PM
Randy,we are in roseville Ca
We keep Gatsby on the sacramento river just up stream from 1200mi.of great delta boating,and 65 mi from SanFrancisco bay.
Looking forward to sharing your progress.

08-10-2001, 07:04 PM
Just a few comments on rot and such:
- Dry rot thrives in temperatures at or above 70 degrees (F) (more or less).
- Dry rot cannot thrive in wood that is drier than about 15% or wetter than about 30%. These numbers are from memory so Mr. Jagels info may be different but you get the idea. By the way, percent moisture content referres to the moisture in the spaces between the cells of the wood. These are the same spaces you keep trying to fill up with tung and/or linseed oil (which is one reason why soaking the wood helps to prevent rot.
- In 1953, the Division of Forest Pathology (Feds) conducted a study for the U.S. Navy entitled "Decay Studies in Wooden Boats and Ships". In this study, they examined some 550 ships and boats ranging in size from minesweepers and tugs down to dingies and wherries. Most of these boats were built in a hurry during WW II. Examination revealed that the materials used frequently differed from the specs. Most common was a tendency to use red oak for frames instead of the specified white oak.
The long and short of it is that they discovered the following truths: Protection from rain was essential; ventilation, ventilation, ventilation and more ventilation was even more essential than protection from rain; salt water had the predictable effect of retarding or stopping growth of fungus. Note that throughout the entire country, they could not find one rowboat,dingy or wherry that suffered from dry rot. This was due to the extreme degree of ventilation an open boat enjoys -not due to maintenance (remember that these small boats were chiefly used in shipyards where they saw hard usage and very little maintenance)!

08-13-2001, 09:17 AM
Thanks for the info, PugetSound, after what you've said it reinforces what I've been thinking about my current boat (and this possible future boat). These Trojans depend so much on "passive" ventilation and I've been contemplating installing a continuous duty AC exhaust fan in the boat that I can use to provide some better ventilation through the bilge areas when I'm on shore power. We keep ours covered and out of the rain/weather, but the humidity is high enough here in Missouri that some better circulation is bound to help! (Sorry for the delay in responding, I've been playing at the lake all weekend) Randy

08-13-2001, 10:45 AM

We're almost neighbors ... I'm on the Alton Pool in St. Charles ... on the Mississippi.

There will always be issues to deal with on these things ... as you know.

I've got a 35 CC Cavalier Aft-Cabin- 1964 vintage. Covered slip, well-maintained and well-loved.

Ever year there's something "wood-related" that could "stand to be fixed." Depending on where/what, it may get put off to the next year.

The only water in my bilge is whatever I happen to spill in it. Not a drop. Course, I've heard that a little water is good ... maybe I'll run the hose in her.

I am very familiar with the model you are looking at. If she's got solid planks and solid/decent wood around the windows/superstructure, then go for it. Unless they're asking too much. Obviously, get a survey.

A good bottom job will get you 2-3 years on that boat in Missouri (even if you leave her in all year). Unless you are really anal about small nicks/smudges on the hull paint from general use- then 1-2 years is max.

Covered docks are a blessing- I'd NEVER own a wooden boat without a covered dock.

Welcome to the forum.


08-13-2001, 11:30 AM
Thanks, Brad, I haven't been on the Alton pool area yet, but I've got a friend that's been wanting us to come over. Does your Cav have a plywood only hull or is it plank over plywood? I'm pretty impressed with the condition (hull-wise) with this one I'm looking at and it seems to have the water locked out pretty good. The price is right, but we're still working out some of the "details" before we can make it a done deal. Randy

08-13-2001, 02:43 PM
Plywood on frame. No planking. (Makes it easy for people like me to work on!!)

Anyway, good luck with her.

Let us know how it goes!